• What’s the difference between an Autoflower Plant and a Photoperiod plant?
• Photoperiod Plants (pros/cons)
• Autoflower Plants (pros/cons)
• Which one is for you?
• Autoflowers are NOT for Beginners!
• Growing Autos Outside

What’s the difference between an Autoflower Plant and a Photoperiod plant?

When you’re starting your growing journey, the biggest choice you’ll make is how your plants “decide” to flower. Here is a quick breakdown to help you choose the right path for your garden.

Photoperiod Plants (The Traditional Choice)

These plants are light-sensitive. They will stay in a “growing phase” (veg) indefinitely as long as they get 18+ hours of light. They only start producing flowers when you manually change their light schedule to 12 hours of light and 12 hours of total darkness (when growing indoors). Photoperiod plants grown outside will flower naturally when Fall approaches.

Pros:

• When growing indoors you have total control. You can keep them in a “Veg” state indefinitely until they are the exact size you want. They can get REALLY big (especially grown outdoors in the ground).
• You can clone a photoperiod plant.

Cons:

• If even a little light leaks into your tent during the “dark” period, it can stress the plant out leading to bad things.
• Because of the 12/12 light schedule during “Flower”, it can be difficult to grow other types of plants in the same space/tent.
• Photos can stretch a lot leading to unpredictable and unmanageable sizes when grown indoors. Plan for your plant to double in size when you switch them to flower mode.

Autoflower Plants

As the name suggests, these plants flower automatically based on age, usually around 3 to 4 weeks after sprouting. They don’t care about light schedules—you can leave the lights on for 18, 20, or even 24 hours a day from start to finish.

Although some people can have success with transplanting Autos, it’s generally considered best to plant the seed in its final container from the start.

Pros:

• They are often faster to harvest and generally stay smaller than Photoperiod plants, making them perfect for tight spaces. (Though I’ve seen some monster Autos in my day!)
• Easy to manage multiple Autos in the same tent/room because the light schedule never changes.
• Autos often use less nutrients than Photoperiods.

Cons:

• Because they are on a “biological stopwatch,” you can’t pause them to fix mistakes.
• You cannot control the overall size of the plant which might be problematic in tight spaces since some autos can get pretty big.
• Stressing them out can cause them to flower prematurely, often resulting in a very small plant. It’s important to know your stuff when it comes to Autos.
• You cannot clone an Autoflower plant.

Which one is for you?

Choose Autoflowers if you want a faster harvest and don’t want to worry about light timers.

Choose Photoperiods if you want maximum yield, the ability to “clone” your plants, and more control over the final shape/size.

At a Glance: Autoflower vs. Photoperiod

Feature	Autoflower	Photoperiod
Trigger to Flower	Age (Automatic)	Light Cycle (12/12 Change)
Average Speed	Fast (8–12 weeks total)	Slower (12–16+ weeks total)
Plant Size	Usually compact & Discrete	Can grow very large
Difficulty	Difficult*	Moderate (requires light control)
Control	No control over growth phase	Total control over growth phase
Best For	Small spaces & quick turnarounds	Big harvests & tinkerers

Autoflowers are NOT for Beginners!

There is a common misconception out there that Autos are great for beginner growers. This is not true! Except for the part where you don’t need to manually switch them into flower and set up timers, this is really not difficult to do anyway thanks the availability of Smart (Alexa) outlets.

As mentioned, Autos flower based on age and will reach their full height, assuming they’re happy! If you piss them off they WILL flower prematurely, often resulting in a 4″ tall plant.

Irregular watering, fertilizing, light schedules, temperatures, etc can cause your Auto to flip out and start flowering prematurely.

You also need to be able to read the plant and diagnose deficiencies or problems correctly and swiftly to be proactive since making mistakes here will disrupt flower production and overall quality.

Growing Autos Outside

You can do this, however there are a couple things to keep in mind.

Transplanting an auto is risky. You can try using fabric starter bags to help mitigate the transplant shock, however I have stunted quite a few Autos due to outside ground and air temps being too drastic (whether planting in-ground or moving your indoor pot outside). You really want to try and avoid shocking an Auto as much as possible and dealing with unpredictable weather can makes things very challenging.

Since Autos do not depend on the changing season and waning sunlight to flower, this means your Auto will usually flower during the hotter parts of the summer. This can be challenging when trying to preserve terpenes.